SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbac6644c4253b8c416874873fe8e0d14197cafde04957dbcae282d54c151515' 
  AND token = 'On0gGYMrwf2OWuSCMyyrgOD9DfmyXNlClWRv3y3tB7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}