SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73b137a1e52af96b3d47775b9c1ead84e6ef78949e9fe8396ad7d561946204a3' 
  AND token = '5FqgVTwYdPYzXdZx4cslpy/6opbDtNgN1ohMkczjvzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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