SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c26c8a4cbddeadca594e2c2a0a50d0e58adb60dada622d587528543c147ba5c' 
  AND token = 'X3X+Ax1ziido6XRGrMUEYiVA8Vf5YNWdjHV+N/mnIiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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