SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9205c0e5e9c2a96c752d30cd9f8717a02ec500fedbc09063aeee6a8eb7d0264' 
  AND token = 'FTRnPLZpfGbKxFNH7fwypzvzC5BD3zgePanDetgErxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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