SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8903313da17fe106f5f68e81e6183e24a6b014f2eed2cbee6caed3926aa57275' 
  AND token = 'YFSEifupK1cflXNnFsegmbDtQSoNDDdyaQhy1v/Tpcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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