SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29b78a4c26693ee9b0e2cc48a5b79fed38eb5d57d54d3df37f6dd91a790cecb9' 
  AND token = 'Uw7WSoFJtKs84uYTnrPmtLdmJRWd9Oucf37F6vu/eTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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