SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bf313b8c76e5f89f68a401a4d0357c78e81e292935e4bcb5f4e65aa96334665' 
  AND token = 'isoLOpKKTxHYqBCAKVQMRg88/7AJmGPaluoy/icAUCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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