SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd089cb7c20d9d801b095c3be8b281b571519b868e2f9e661dfb63fdd1a249603' 
  AND token = '6d5VuNoYOFPFuK3urIxf47zKT3wTWVrrHPWAEDhPH7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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