SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb04e2f2369a67a50d08ab3390b66d3315d80f24681646aa7f98e672de47ef9e' 
  AND token = 'BRoH0TcsJeqbGmS7w7JHOOVu1VKqj/qamS5ozCucHQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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