SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e30139270a21ad88c4b48425b45c7882e3007ac2aa1f53cb6494097794de996e' 
  AND token = 'WUxwh6Nd354t1Xzcuv51tG8HBzXSYJGgM2HocflcR2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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