SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c8a97263dc0af601ee261460d3ee6396e2b08fb245ed97eb9f871605a567551' 
  AND token = 'atZbkil1hK2SCYSBxzQI7Gic9MnKkoA3ZwLRjksWBfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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