SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5961dd69b9590374dc741a8518e84d573f03c37d336a262fca368ac930425d9e' 
  AND token = 'Qu7q5zLNdNbfE6i4J+Em+DPuptJJ1Im8Wj+xQwBTVDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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