SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '676fb4b530bc070a9abe0ba490ce03c552a06800959956288839fce95f647ff1' 
  AND token = 'pv2u9KS5yApwouEnilNqPEwBOeoHOCcPKiM/BW3ujV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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