SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef9db44d8885cd8f405bdb67f21a7cd8d7fb6b5cb0569e1b94a59e00b67bbc3f' 
  AND token = 'IMrKAHDMxOoGb12rA+R2j2FeLE72nqrfBh53a/Puw3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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