SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e96f79f3cd70c79a94cf42b18cfc09a67068f7825501e64859d5807c009d7fa' 
  AND token = 'psf1YrsDA2niwCzE03zzVrS9Si/ovRia6bD92TFiZdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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