SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a5573c0f3b619f5dc6a2a1ffdd86de8c60946416fb97e4f12b8593fbe073c6f' 
  AND token = 'zNFLPB0j+oERDAF29qZTyN7/3BbTGlLDXjPYVUwpZr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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