SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ca2c9470acb65a5237f8f54de80b4ab752018a367ca16f687d81ab042198ddd' 
  AND token = 'yKHia3F1FHVTteiwht1B56IUOgw1E+IKCSC8ONxEfRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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