SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ec486e23083dcc7f25690bd8a1729d12840815507be11d3a708008d32b3b17b' 
  AND token = 'PzZitjmhpeV3/8Iy07uYe3O9ePjVyrxM3sXESh2PwSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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