SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce0b2987e7f6c54eb94090113aa77d413b10688b945782542d623cf49cb9aa1d' 
  AND token = '0FzzGOar1hHhm7MY12/H4QSgmUYlKB8j1rV6jUc/Uc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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