SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bffd4fb3d72870b70c38245110cc85467debdd6f553425b266d75a051330a2ac' 
  AND token = 'JGw2k+qR8RXyuDMGSmNcByQKHqjLZc1Zk/eSoP90Fxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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