SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4174f2cdeaf2ba44c597c4ef089ad5de91699293aa1d36d143658ee63845a76' 
  AND token = 'GbUkZUTjGcTF1lXNEyDVc/bxQxZRNbjJQhl2yht+uxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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