SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c131d6b012a0263776680df600659c692dae83c98d026a2bc3b10a18eda39fee' 
  AND token = 'ZStvbydWcF/cKDRYgF/m6bq6sZCpPfVmDohtTq/dS0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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