SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd59e3b98212699e4dd131941c976b123efe89285662ba27f88219e208d1064ee' 
  AND token = 'SOnIeOAzLfsT61IZQ4s4mmcb+JPxDsieeUPMuWdKxXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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