SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bbb0a4acf0f8bafe393af787467b61c59855352ac6cec35423a87f94ddd41da' 
  AND token = 'WfpxtdwyXc5MyNUKg94n+bzDBwUP26RdNm5kPsrxgX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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