SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a989787d77298922d1d555c14e59c3f2daecd5d4d16d5bfbe5af6ddba9f421c' 
  AND token = 'RaZaOTgAwOFXBi8vhBWmRavcoHnXwEsj5akgRa61S8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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