SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44aadee1ba0ceaac668f13be7ee72450372bfb3bbfc17feec5845efad6995be7' 
  AND token = 'ySYw5JenPyvcSWT3aIOZ95KuWFuV4ee53gpP0ihiRlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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