SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea4dc263367471594f23a0cecc0b90e23c2e6491cfa9995bf6beecadeda4236f' 
  AND token = 'IaHdL7d/hmGl8sVFq8pgDM7gvT3nkper7yXt8vsEs1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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