SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c3b9fa087e416ee60efbc40556477fee45697fa6900a2f346a8d010461bab3e' 
  AND token = 'D6MwiRjGXmoQ/X/4XANFqC/VzoBKJDKBClF7BUXvq4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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