SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '607cb51bc6684e32c4a4042f09a1954cd9fd95b707b88184043a7aea1e9a0fa2' 
  AND token = 'ieB9oESVkt2C3AOkELzPbqQ3gwS2pkQ0Wr09ns6F4lQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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