SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c1112598f21a913aaf2d3279afef1e4872e1a6b0590179bc003a643a6963db3' 
  AND token = 'hzXsvNFjpwauaHN1jLts3c2C4bhe6vqt9cuUXAblfTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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