SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a506bb60d6571c7f18f9ffaba5a1a89392565aca47478e81acc23d09ecc4b3f7' 
  AND token = 'wE+qzGlC5H2wuie+0fo10DrbVivpmKiONuhsSNIQcJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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