SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93da68e3b138f29e3072385a6dc186809966ddd43f9ccfd6a8583258830b499d' 
  AND token = 'UQ9HUTNNNqIxCdy/HUAfjgrzoWW9YJuxXsJQim/B33A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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