SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1e0f42b33c67ecbb52579e239fdf3ffc61703781d9984b5f8507d92b46419c9' 
  AND token = 'nWKT868U8z4zT1iEaqq0rgjgkP4PPQ2hubZLvqJCkoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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