SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ae322cf955756a4026209e893b6cabbf6b0f38b54c2644e9a0ca3afa91853dd' 
  AND token = 'ncT8fVbLYbtc5/wSKpCMLe9Nijf91fc1ytgSYAZQuWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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