SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38fa3531e14137416e74719bb262fc56926f9a9fde400f0cd271fd66216da376' 
  AND token = 'tBEnIudf1v1J1g/9HlTKhGUzyvmRznzVN8CjHCoqii0=' 
  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"
    }
  }
}