SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a139163af8600250aa63aeec334891fb14d1f62c629c0b271f15d275b869226' 
  AND token = 'NmvHT+LUy09AtSM6txDFdCGxeZOH9SWIfzqWY6/Ctx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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