SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a6315a3673f9113a8966990be259fe8a88b2ee8afc2c9f9d29de2da507872c5' 
  AND token = '5ur1P7tQKDKXNa6/2ELFuw3bkTCTkgXbguD1Sl0H3k4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}