SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd280553f3823cb1223def80a3a9a32fec7a1eb46090ba313b329ab7184e3030e' 
  AND token = '1GBw67+FMI+QAeli6Uwg0oSbp4dFSKRL2UBcQtkSAOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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