SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '661c89663465ef08ef2401f425cc58b80eb58ff414b516b65277c245e09503b5' 
  AND token = 'pvTwXJJYFWmFUEkZfg9j9ozKAgvVja6au1Z0TrUxMVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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