SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd09491264b00b5d8c44101af3f256de638497f4b85adb6f8c68c331095bca73a' 
  AND token = 'LmmWIL66HRNXI3ObewLJrZWKfw4x1ZxU4PjzpmEhqiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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