SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9307c82a844c42252d69631febffa4ab06ffa98459f9133457a74db0a729b862' 
  AND token = 'uKgd/QxGYlap/KsJHbTKyGBlOnBnUOVyWuc2tw+gLZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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