SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4469513fff150daf88cf717dda7659346375efff5f2de4acbc90332f610b3ddc' 
  AND token = 'Bv+8/zX0FPxcVEQFfAmmXhe4bWLfq6fnOLLAnvaHIZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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