SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1673108f0457c8cebe1e92275f60d1d389f335528802c525eef50f5a9274f9f' 
  AND token = 'JESSJJBLA5OhLnAzohTNbVG2zKOTQXCoAGBeY49U47g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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