SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cadf970243c883fbf26a2cd7c2db780342afcec7340f19958ede9a2dcfaef32d' 
  AND token = 'RknfIFryZS7andhcY5rDzhcRCqYCcXCkkY5/WWa+X5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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