SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45044817fc9e562f86194eca658cd3368834feadf7db52cb9b215ec842cb89f7' 
  AND token = '6V60yRYLdWLdTzJJsP6cLgXcEqUoNtO+BGwenJ/TD5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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