SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '216943f883ba17989f18cf9e235dd9290fac501080c4cb4470c12dd49bc676cb' 
  AND token = '4JTNp3FTKMTlQCVufRMcVrpmFHJ8GzhkQjXlzSYPIMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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