SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de069949f63de4364fd6ae7b0d7fb4293d85bc8c87c692f1a9bce223784c3217' 
  AND token = 'TOwPheSFQR2YQPGrzcZ1dOMY2rfCwEBna2VznmrhnEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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