SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db1d7d37e744fce2991f780642de96c62cefe7ae4df5b25b0345c92063310ef8' 
  AND token = 'ULrMU2tNp5A7c6rWDVZlxo0pFtOAgQZUI9aCyBJmwhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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