SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92ade9a118448f35dfd3256721ce4c438b9ef02522c8339b920202bacd37f6bf' 
  AND token = 'YG443TnY3I6qydNLleMVTeFOJCnQegyMLKaSsanyiA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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