SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c5c88d28324aa2b6ea4b9d5b76748a673c214b436de354d58ee46dffab8deeac' 
  AND token = 'zGvNJ6cMCXPcEd4TDnLbfdvb4SWNz6sElvYtUhhG1nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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