SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f893a60a54f2af6c6c2c0f659308bbc3572ccf4e72dd6f1c6974d5b702e30df7' 
  AND token = 'bN7LUHM6GnWOi6qZFwEU3YLnmKfdZluFwCHnTrddh2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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