SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f20f25a6b5f94fc59f8accd443e3ecd5e76a5f019699b4296bfd68b2b68f170' 
  AND token = 'GKvRnYzRnEMv/BrYiHrw+idvOGGQpbWP9HrgQtPvoDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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