SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4af5540fe79339e54c71671c3fbfd435117431b2ff87406b239d515bad6e87f7' 
  AND token = 'hJpuKepkaku00NDemDTnLOmVWlKgsaGGNz8Z5PAYtN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}