SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3336ec0fe17eb2c93d24ac61e24f0b83f9e0cb5fa634e5f2183675b70174a360' 
  AND token = 'pV8DqAscojtnmptY9+BvP69sH8SDPe6UO1LBkgdVvAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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