SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c485273d6b9fe061787e48de85638007bc64a4ea1dc6890a933b500cf80db8e1' 
  AND token = '4RznRt/2rve5UjXSTmqbUiwBmFyZuhbohZaFEp8WQdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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