SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5014e5a250264b6c38ef1e729ff3b9520120866eebd7147fadd69f3794e1253e' 
  AND token = '9Q9sDvsgSn/BgP1WpTg7kgjfb7DwJP+lMRmroGX2tqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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