SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0acf4fb0b9154ab7db99bfbf8e39cb11b2dd0e493dbd689f48b220a4ef4df74' 
  AND token = 'KgqnFblPgHGko4jQ3QDBxzgsrFs9ImQ8b1MmRWy2y6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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