SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2f5dab30dc0587ca8459c39cd10af1365d28def6ffeea86618f67271bf408a6' 
  AND token = 'uXJlwZOhhgLUIqldwmVSUQakXsjUY6wIGTgWSC4tS3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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