SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c73ad88e12226e43caaaa2ace0eb6ee24ad8fa76e8fc408613f256bd2f22f65' 
  AND token = 'f0y9VPWbQbDpbPJkA04UKAPspCs1XHYEru8L9jD7FIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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