SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d04e7126892c30fda77bad2f4f75c5cd0b543ecfdde5520566cc58d446d974c' 
  AND token = 'xT+/3e34R1gmyOKoeh4zrZVenfpSfUZJQiwCplW2Nsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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