SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e661074d11deb8224dbef5f6033a44f04739c1cd8e34a9ca357b7f1e0d3d2ebf' 
  AND token = 'gWyjbrMTaq6dAPMQqR+fKXbpFhxoZofrCt1XcR2oMns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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