SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b02f8bbc4a261ee3592a1eb4e39eb51639c37f7687791a93ab2d67c5a10c551' 
  AND token = 'lhbUDippVVJpJXYnfFU6FQ8pv6PWQ71GKHqi6KDEdzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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