SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59cec0a9743f8053681cde3e31b382fdb2eac4983015853117d7279be5ffd59d' 
  AND token = 'RIRfczvOqpnMrpfjjzdahmAM/pn3rE014hJ2oQz0xLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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