SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd59138caac75e6510b6f91d45481f70eccd86684ea3e4fd188ff2bd58393041c' 
  AND token = '8xPEyCd6EmGSOdyKoCGBhHwsbK0a4rIL7VFUkdnJoXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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