SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e57a985dd5937edf84ebc18e02f80228360f550ef16312bca4e07b9372c39f6' 
  AND token = 'lOKk6fdMfF3QUrsQKSPfdAvxhXoET7/zSUDQWpIPgJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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