SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66de6defc391649565c0897fd995680f23dc34c1b1bcccf7f7f859807947e85d' 
  AND token = '/QvIGCsZm5dCI8Z7EIhJbIY/2iuL82peF7wOOH+lDoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}