SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4eb9747a5ba854436f768199560eb9bce36dfae99cd5ad2c7598a85e1414ceb3' 
  AND token = 'WXdk2HkbeeFAkfXpUUg90bcbu6jsmfpYAqwW3bXGv4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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