SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8d93d9bfb8ec20f86d78b891c437905d463605242b0d9e8cea307cdcda7e126' 
  AND token = 'FVIAhV9YgomzPtZX1sqdPgV+Lh+JFfBvZd+Me8r5NJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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