SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5667f9ee1ae94faa9339cdb4eb05f2c19d39af14c109aa191e02c7c731b22d91' 
  AND token = 'katH4f2Mkt8e0/5j2if0AvLqut9cgbP/sHELaOqoN14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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