SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b72c19717858cae0c6572195f23dfcdc9ea4349387c9e890730bfbbb1758159' 
  AND token = 'l5cTVF8ICyEVH6YLtRu9minJSAp6zJRbQuIEc+qk4Gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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